Logo
FULL SITE MENU

How does the oil get into the water 1977 MD7A

J

jimsmd7a

New member
I found a lot of water in my oil today The color of the oil is grey,and the oil is now overfilled by about 1 Quart. The engine is a 1977 MD7A which has always been cared for and alaways ran like a swiss watch. Is is possible that the seal in the back of the raw water pump could have gone bad which would pump water into the engine,or is it more likely that the block or the head has rusted from the inside out.
 
Hi, I had the raw water pump seals fail on my MD5A. Even though there are holes to drain water between the water shaft seal and the oil shaft seal, these quickly clog up with salt crystals/corrosion, so then it's just a wait until the oil seal fails...
When this happened to me I rebuilt the engine, suspecting the head. A year later the injector spring failed. Lesson learnt - hard spring steel doesn't like even the smallest amount of surface rusting. I have also bought new valve springs, because if these go it's game over!
 
Col was right........... It was the head gasket. One of the water passages next to number 2 piston is only anout 1/8 of a inch from the cyl. Somehow it rusted through. when the engine was shut down the water in the head would drain into the cyl and drip into the oil.
Most of the folks that I spoke with all said to junk the engine since it is raw waster cooled. It rusted out from the inside into the crank case.
Luck for me I pulled the head and saved many thousands of dollars.
Thanks Col for the good advice.
Jim
 
Back
Top